Russco, QRK, Sparco, Garrard, Thoren, Fairchild, Roberts

No I haven't used Dynamat, BUT I have used black hole and a few others.

Dynamat will work just fine. So does the spray on TV that seals gutters and BOATS. Flex Seal. Tape everything off and a coat or two.. Same with the platter. You can use silicone too to get rid of the ring.. (the bottom)
The top FELT is exactly what it's for.. noise and a slipper Que..

I've seen people cut one two or three groves in the top platters side and fit dampening O-Rings too.. Add or remove, for the dampening you like..

Lots of tricks.

Those tolerances your talking about are for a turbo rebuild spinning at 20-50,000 rpms.. LOL. remember on a TT sloppy is good, too tight is not..

The platter bushings get loose, but seldom are TOO worn.. I've seen water damage wreak havoc though..

Drive bogies that's different.. I've seen a LOT of those with no thrust or wave washers to preload the drive wheel. the type of lube is pretty important and KEEPING the lube on the bushing is kinda tough just because of design.. My little axels for the drive hubs have a reverse spiral cut up the side. it helps to riffle the lube up the shaft as apposed to not at all or down the shaft.. O rings and wave washers seal the bottom.. kind of... :-)  No squeaky tight.. loosie goosy is a lot better.. :-)

Aren't they the BOMB.. Everybody need at least one.. I love um..

I'm thinking a 2" acrylic platter on top of the original platter. Just match the tonearm perch with the thickness of the platter addition. We're getting serious now... the more we do the better they get.. They are that good of a starting point.. people don't realize how quiet you can really get a TT platter if you just think about it.. How you drive it is different too.

Can always use an external drive motor and O-ring drive belts too.
Fill the bottom of the platter with silicone and that's about 3 or 4 more pounds added. Dead quiet then...

I like the secondary isolation of Thoren 121 and 124 system.. Belt, idler AND gummie puffers between motor and chassis. Boils down to the platter bearing as far a rumble.. ONLY.. Fun being a mechanic..

Usually.. ;-)

Regards..

Armboards 25.00 aluminum. These are usually available on Ebay. I've purchased 4 or so.. For 25.00 you can't beat the price..

https://www.ebay.com/itm/224429491252


Regards

I have one of those armboards coming next week. I'm waiting for it before I drop everything off at the powder coating guy.
Actually, one of the nicest spindle bearings I've worked with was on an old Pioneer PL-41D belt drive. Spindle was aprox 3/8" in diameter and very finely ground with an integrated ball on the end. The bearing pad was shot so I made up a new one out of Delrin. The bearings were bronze sleeves, not oilite, finely honed and they showed zero signs of wear. The amount of play was extremely small, I didn't measure it but well less than 0.001. My guess is that they followed the rule of thumb for plain bearings, 0.001 clearance per inch of diameter. So it was probably around 0.0004 clearance in that bearing. Using light hydraulic oil for lube, with belt off it would take over 3 minutes to spin down and come to a complete stop. Totally silent as well.
If I get noise from this bearing, I'll redesign the spindle housing and make it out of aluminum barstock with a bottom cap so a Sunnen hone can pass through. I'll use bronze bearing stock for the bearing sleeves and do the final sizing with a hone to get down to 0.0005 to 0.0007 clearance. With a Delrin thrust pad it should be completely silent.
With no oil in the spindle and having 0.0013 clearance, my spindle feels very loose. Because of that I will be running a heavier weight oil in this unit.
I think when these tables were designed they worried more about reliable operation than fidelity. A seized spindle was simply not tolerated, hence the very liberal clearances.

Well they sure can be HiFi. A few companies used these chassis as their base unit. The pocket spindle housing, just black hole it. I’ve rapped them with 1/16" silicone or neo rope too. Little dab of silicone hear and there to hold it in place.. Quiet as a mouse.. Add a different visual when you look at it too.. The ol ? will pop up.. LOL

I’ve never seen one lock up, BUT I have seen water damage units..

Couple time there were fires at local stations.. Fire department and water... I had a couple of those.

I just picked up a parts unit.. 75.00 typical broken idler and the wheel missing.. All there though..

I really got my eye on a Fairchild 412, 600.00  I'm thinkin' 300.00. :-)

I want my old 750 back.. 3-10k for one now..

There are after market idler brackets from Europe that sell for 50 bucks and there is a guy in Thailand that I purchased an idler wheel from, listed at 75 bucks or make off. I offered 60 bucks and it’s on the way for 68 bucks shipped. He advertises on Ebay. Look for past listing or search seller name windkit.
The idler wheel that I purchased looks like a high end Audio Silente wheel that uses an o-ring for a tire. My buddy that has both a Thorens and a Garrard swears by that design.
Check on Karmadon.net for the bracket.
Or, I’ll pay you 100 bucks to get that broken TT off of your hands. LOL Even pay shipping.
BillWojo